SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68c6f038d24349c29fa2b28f52c840518188554d47a830111d00d8fd0cb3843c' 
  AND token = 'tTotLW77XIYq75bv3guEh3Xd06u7lDmDegA/VFIPOSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}